0=-0.011x^2+0.99X+1.6

Solution for 0=-0.011x^2+0.99X+1.6 equation:

0=-0.011x^2+0.99x+1.6

We move all terms to the left:

0-(-0.011x^2+0.99x+1.6)=0

We add all the numbers together, and all the variables

-(-0.011x^2+0.99x+1.6)=0

We get rid of parentheses

0.011x^2-0.99x-1.6=0

a = 0.011; b = -0.99; c = -1.6;
Δ = b2-4ac
Δ = -0.992-4·0.011·(-1.6)
Δ = 1.0505
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-0.99)-\sqrt{1.0505}}{2*0.011}=\frac{0.99-\sqrt{1.0505}}{0.022}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-0.99)+\sqrt{1.0505}}{2*0.011}=\frac{0.99+\sqrt{1.0505}}{0.022}
$